The bombs, which were planted by the roadside, went off seconds apart and targeted riot police routinely deployed at the location, in anticipation of near-daily protests by students supporters of ousted Islamist president Mohammed Morsi and his Muslim Brotherhood group.

The slain police officer was a brigadier-general, according to officials who spoke on condition of anonymity because they were not authorized to speak to the media.

The blasts also wounded seven people - four civilians and three senior police officers. The wounded included Maj. Gen. Abdel-Raouf El-Sirafy, the deputy chief of police in the Giza province, where Cairo University's main campus is based.

Egyptian state TV said the bombs were crude and homemade.

The attack takes to a new level the violence which has come to define protests by students in the nearly nine months since the military ousted Morsi.

The military-backed interim government has branded the Brotherhood a terrorist organization, alleging it has plotted violence since Morsi's removal. The Brotherhood denies the claims, saying the prosecutions are intended to give a legal veneer to the removal an elected president.

The government this week put the death toll from such attacks at nearly 500 people, most of them soldiers and police.